


What is the powerhouse of the Cell?

by Muffinlover246



Series: Destiel Fanfiction BINGO [4]
Category: Supernatural
Genre: Alternate Universe - College/University, Bingo, Bottom Castiel, But it's there, M/M, Smut, Studying, Top Dean Winchester, Topping from the Bottom, very little plot
Language: English
Status: Completed
Published: 2018-03-07
Updated: 2018-03-07
Packaged: 2019-03-28 01:20:54
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,326
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13893234
Author URL: https://archiveofourown.org/users/Muffinlover246/pseuds/Muffinlover246
Summary: Prompt: College AUCollege AU where Cas and Dean are in the same Biology class. Cas is passing with flying colors but Dean is struggling so Cas offers to help tutor him one day…





	What is the powerhouse of the Cell?

**Author's Note:**

> This is the 3rd part of my Destiel bingo.  
> This weeks prompt was; College or High school AU
> 
> Hope you enjoy! <3

“I hate this class!” Dean shouts as he slams his textbook closed. He puts his head down on the desk and groans. Dean has always hated Biology but now he was expected to learn all of photosynthesis and respiration.

How is any of this actually important? It’s not like I need to know how I breathe in order to do it.

“Dean?” Cas says cautiously, walking over to Dean’s desk. “You okay?”

“No.” Dean mumbles into the desk.

Cas places a soft kiss to the back of Dean’s neck, just below his hairline, and Dean can’t say he isn’t grateful for Cas being here in this moment.

“Do you want to take a break?” Cas asks quietly, his hands rubbing up and down Dean’s arms.

“I wish.” Dean says before picking his head up to look into his boyfriend’s ocean blue eyes. He’s wearing Dean’s sweatpants that ride impossibly low on his hips. Dean pulls Castiel’s face closer to his own and brings their lips together in a soft and coaxing kiss.

Cas moans softly before he pulls away, “Are you sure? Because your body seems to be telling me different.”

“I need to pass this test Cas.” Dean says, opening his textbook again

“I could help you study.” Cas says closing the book in front of him.

“Fucking each other senseless isn’t going to help me tomorrow.”

“I’ve taken the class before, Dean.” Cas says seductively, as he runs a finger down Dean’s chest, “I could be very helpful.”

“Oh really?” Dean says, leaning into Castiel, “How would you help.”

“Well, we could play a little game.” Cas says, straddling Dean in his chair, “If you get an answer right I’ll reward you but if you get one wrong, well…”

“Well?” Dean asks curiously.

Cas leans into Dean’s ear and whispers, “I’ll leave that up to you I suppose.”

Dean contemplates this before he ultimately answers with, “Okay yeah, lets do it.”

~~~

“When you suggested strapping me down to my bed while you give me an biology lesson.” Dean says as he pulls at the blue ties currently keeping his hands at his sides, “I figured it’d be more fun than this.”

“You don’t think this is fun?” Cas says as he turns on the vibrator to its highest setting inside of Dean. Cas smiles wide as he watches his boyfriend arch his back with a shout, “Because this is really fun for me.”

“Why did I agree to this.” Dean says through gritted teeth, attempting to find some form of relief by grinding down on the toy inside of himself. Cas turns off the toy and leans over Dean’s face, still smiling as Dean whines at the loss of the vibration. “C’mon Cas…”

“Tell you what,” Cas places a soft kiss on Dean’s lips but pulls away before Dean can get too deep into it. “If you get the next 15 questions right I’ll give you one of the best blowjobs you’ve ever had.”

“I want more than that.” Dean practically whines, “we’ve been doing this for like 5 hours Cas.”

“It’s only been 45 minutes Dean.” Cas says with a soft chuckle, “What do you want as your reward if you get the next set of questions right?”

“I really want you to ride me.” Dean says unashamedly and Cas can’t help the twitch his dick gives at the thought. He loves riding Dean, the feeling of pride he gets as he sees his lover transform into a quivering mess is incomparable to anything else he’s ever felt. “But I really do want that blow job you promised.”

“Well if you answer the next 20 questions,” Cas says, bring his face closer to Dean’s so his lips are just out of the other man’s reach, “I’d be more than happy to do both.”

“Okay, yeah. Let’s do that then,” Dean agrees and Cas sits back down into his chair with the biology book open in front of him.

“What is the formula for photosynthesis?” Cas asks.

“6CO2 plus 6H2O plus light energy equals C6H12O6 + 6O2” Dean says quickly, grateful he actually knew that answer

“Good.” Cas turns the vibrator back on but only to its lowest setting. Dean moans quietly at the sensation.

“What is another name of the anaerobic respiration cycle?”

“Fermentation?”

“With all that beer you drink I figured you’d be certain about that one.” Cas raises an eyebrow, hiding his grin with the textbook.

“Oh, shut up.” Dean retorts and Cas retaliates by turning up the intensity of the vibrator. “You're having way too much fun with this.” Dean says when Cas turns the toy back down.

“Maybe, but in the end we both win.” Cas moves onto the next question, each one getting more and more difficult. Dean however, is able to answer each one fairly easily and though he gets confused on some parts Castiel thinks that so long as he doesn’t have a vibrator in his ass during the test he won’t have a problem.

“You ready for your last question, baby?” Cas purrs as he straddles Dean’s hips. Both of them now gloriously naked. Cas wraps his hand around Dean’s erection, bringing it to full hardness.

“Yes-fuck- c’mon.” Dean moans

Cas leans down and peppers kissed up Dean’s throat until he reaches his ear, “What is the powerhouse of the cell?”

Dean laughs, before he turns his head to kiss Cas, whispering the word, “mitochondria.” on his lover’s lips.

Cas moves his hand and begins rubbing both of their cocks together instead. Drawing matching moans from both men.

“Do you want me to untie you?” Cas asks when he pulls away slightly

“No,” Dean says with the shake of his head, “But I do want you to make good on my reward.”

Cas grins at Dean before his makes his way down Dean’s body, peppering light kisses along the way.

When he gets to Dean’s erection he wastes no time sucking down the entire length down to the base. Dean cries out and Cas hums in affirmation which only causes Dean to buck up into Castiel’s mouth.

“Fuck, Cas-” Dean curses, pulling at his bonds, loving and hating that he had absolutely nowhere to go. Cas wraps his hand around the base of Dean’s cock, in order to prevent Dean from cumming far too early. Dean whines is response to this while Cas continues his merciless rhythm on Dean’s cock.

Bobbing and humming on the length until Dean is almost in a state of tears from the overwhelming sense of pleasure. When Cas pulls off he leans up to Dean and kisses him thoroughly, loving how Dean licks into his mouth like he owns it.

“C’mon baby,” Dean coos, “Wanna feel you.”

Cas mumbles something, reaching beside Dean to grab the lube next to his pillow. Cas opens himself up quickly before he coats Dean’s cock with lube.

Cas teases his entrance with the tip, smiling wildly when he sees Dean’s eyes flutter shut. Cas sinks down on the hard length, slowly letting Dean split him open in just the right way.

“Oh fuck,” Cas says when he bottoms out. He waits a moment before he begins to rock his hips up and down. The room is soon filled with the moans of both men as their orgams build and build together.

Cas wraps a hand around himself and pumps only a few times before he is cumming all over Dean’s chest and stomach. Dean isn’t far behind Cas, and soon comes with a shout inside of Castiel.

They lay there a minute as they catch their breaths before Cas unties Dean’s wrists and cleans him off with the leg of Cas’ sweats.

“So, I have a huge exam coming up next week.” Cas says, tracing idle patterns onto Dean’s skin with his finger. “Wanna help me study?”

Dean pulls Cas closer to his chest and places a kiss to the top of his head. “Definitely.”


End file.
